This invention relates to an apparatus for lifting and lowering rod-like material from and, respectively, back into a storage pallet in conjunction with an apparatus for the automatic supply of a cutting machine with the rod-like material. The pallet is, in a removal or withdrawal station, adjustable in its longitudinal and transversal orientation and can be lifted against abutments. The lifting and lowering of the rod-like material from and, respectively, into the pallet is effected by means of at least two lifters which are arranged serially with respect to the length dimension of the pallet and which are movable vertically in unison through openings in the bottom of the pallet. The motion of the lifters may be arrested by at least one cooperating abutment protruding from the longitudinal sides into the inner cross section of the pallet when the rod-like material has arrived in a position from which it may be shifted, in a direction transversal to the pallet, onto a conveyor which then advances the material to a cutting machine.
A system of the above-outlined type is disclosed in U.S. Pat. No. 3,810,404, issued May 14th, 1974. In the system disclosed in this patent the pallets containing the rod-like material are disposed on shelving units which are in alignment in a direction transversal to the length dimension of the pallets. From the shelving unit the pallets are brought with the aid of a transporting gantry over the shelving unit to the apparatus for lifting out and again depositing the rod-like material. This apparatus is designated hereinafter as removing or withdrawal apparatus. Upon bringing a pallet into the withdrawal apparatus, the lifters are operational until the material or, as the case may be, the upper material layer in the pallet, is lifted out beyond the edge of the pallet. Thereafter, the motion of the lifter is interrupted or limited by means of at least one stop member against which abut the lifters or, as the case may be, plate members disposed between the layers of the rod-like material. Thereafter, the rod-like material may be individually pushed in a lateral direction by means of a pushing device onto a conveyor and advanced by the latter to the cutting machine. After the cutting machine has severed the desired number of pieces of the material being worked on, the material remnant, provided its further storage is worthwhile, is brought back by the conveyor into the withdrawal station and there it is again pushed over the pallet. Thereafter, the lifters lower this material into the pallet so that the latter may be sent back to its location of storage.
It is expedient and desirable to use, in the above-outlined system, pallets of identical design. In this connection, however, the problem is encountered that the inner cross section of the pallet when measured in a direction normal to its length dimension is, in a multiple manner, not adapted to the cross section of the material stored therein to ensure that the material is disposed without significant lateral play. This applies also when, of a material layer which, for example, consists of five rods, only a portion, for example, two rods, is used. In case a pallet loaded in this manner is moved by the gantry-like transporting apparatus, the material may shift or roll therein back and forth. Thus, there is a danger of damaging the pallets and furthermore, the possibility is not excluded that the rod-like material shifts over a material layer with a likely result that in case of significant accelerations of the transporting device the material may drop out of the pallet.
Although this drawback can conceivably be eliminated by "padding" the inside of the pallets with a filler material to limit the cross section to that of the material to be stored therein, this measure is circumstantial and is of no use if a material layer is no longer complete.